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Objective: Multi drug resistant tuberculosis (MDR-TB) is becoming a serious public health problem world-wide and have low rates of treatment response, high mortality and morbidity. The present study intends to assess the extent of this problem among tuberculosis patients attending hospital. Design: This is cross sectional study of the tuberculosis patients attending in a teaching hospital. Material and Methods: Suspected TB patients attending hospital were assessed in detail. Overall 1487 TB patients were identified and assessed further by detailed history taking, clinical pathological and radiological evaluation. Culture and sensitivity for Mycobacterium tuberculosis was done by BACTEC 460 radiometric method from sputum of patient with irregular treatment, inadequate treatment, and treatment failure cases. Treatment was given to the MDR-TB (31 in our study) patients and their outcomes were assessed. Results: Between January 2003 to January 2008, 31 MDR-TB patients were treated. Mean number of drugs to which resistance developed was 4.68 (Std dev 1.904). Successful outcome was seen in 64.51%, relapse was in 12.90%, treatment failure was in 19.35%. Overall unsuccessful outcome was seen in 35.48%. Mean number of 1st line drug used in study regimen was 1.39 (Std dev 0.844). Mean number of months when culture conversion was seen was 5.090 (Std dev 0.92113) and that of smear conversion was seen in 3.809 (Std dev 0.813575). Complete resolution of radiological opacity was seen in 9.67% and residual fibrosis in 90.32%. Side effects of drugs were seen in 61.29%. Statistical analysis shows age, inclusion of ofloxacin in regimen have no stastistical significance where as male sex, lesser no of previously used drugs, lesser number of resistant drugs, higher number of active drug, addition of 1st line drug in regimen, use of kanamycin in regimen were associated with successful outcome. Previous use of ofloxacin, extensive diseases were associated with unsuccessful outcome. Conclusion: Multidrug resistant tuberculosis can be cured by intensive treatment regimens but have low cure rates and high cost and problematic in resource poor country. [ABSTRACT FROM AUTHOR]

Objective: Tuberculosis of the epiglottis, an uncommon entity, is rarely considered in the differential diagnosis of laryngeal malignancy and may present atypically as obstructive sleep apnoea (OSA). This rare presentation is discussed. Study design: Case report. Methods: CT scan of larynx and neck region was done initially. Emergency tracheostomy was done. Biopsy was taken from the growth in epiglottis under general anesthesia. Diagnosis of obstructive sleep apnoea was done clinically as per the American Sleep Disorders Association's guidelines (ASDA). Result: CT scan of larynx and neck region showed soft tissue polypoidal mass in supraglottic region, which was attached to the epiglottis with partial obstruction of airway. Biopsy from the growth showed epithelioid cell granuloma, areas of caseous necrosis, inflammatory granulation tissue, Langhan's giant cell. Patient was treated with CAT I, DOTS (WHO) antitubercular drugs. Conclusion: In the evaluation of patients of obstructive sleep apnoea, the possibility of epiglottic tuberculosis should be kept in mind. Epiglottic tuberculosis may mimic laryngeal carcinoma causing obstructive mass lesion in larynx. [ABSTRACT FROM AUTHOR]

Objective: A 6 year old child was diagnosed by clinical, Orthopantogram, CT scan of mandible and histopathological evaluation as an aggressive osteoblastoma and treated with extended surgical curretage. This rare case presentation was discussed. Design: Case report. Method: The patient was diagnosed by clinical and Orthopantogram, CT scan of mandible and two time histopathological evaluation. Results: Orthopantogram revealed ill-defined radiolucent area mixed with radioopaque area involving 34 and 35 teeth which were not erupted. CT Scan revealed ill-defined radiolucency with varying amounts of radioopaque material with expansion of buccal cortical plate. Histopathological examination revealed highly cellular neoplastic lesion composed of large pleomorphic cells having eccentric vesicular nuclei with prominent nucleoli and abundant eosinophilic cytoplasm. The cells appear to be much larger than normal osteoblasts. There is an area of osteoid formation. Conclusion: Though rare presentation and difficult to diagnose but comprehensive diagnostic and histopathological work-up supporting with literature followed by extended surgical curettage and regular follow-up over a period of one and half year is highly effective in the treatment and prognosis of aggressive osteoblastoma in a 6 year old girl. [ABSTRACT FROM AUTHOR]

Objective: Haemangiopericytoma in tibia and lung as a primary or metastatic lesion, is very uncommon. A case of multiple metastatic pulmonary haemangiopericytoma in a young boy with a previous history of above knee amputation for left tibial haemangiopericytoma is discussed. Study design: Case report. Method: Excision biopsy of the bony swelling, above left knee was done after X-ray and MRI of left lower leg. Above knee amputation was performed. Serial chest X-ray was done. CT scan thorax and ultrasonography of thorax was performed. USG guided FNAC was done. Result: X-ray of left leg showed -heterogenous expansile mass in lower end of tibia with cortical destruction. MRI of the left leg-showed a large expansile mass in lower third of left tibia. It was hypointense on Tl weighted sequence and hyper intense on STIR seqence. Excision biopsy of the bony swelling showed features of spindle cell tumor having an haemangiopericytomatous pattern of vascular spaces of varying caliber with spindle shaped tumour cell around. Chest X-ray and CT scan thorax showed multiple rounded well defined mass at different sites of thorax of different sizes suggesting multiple metastasis. USG guided F.N.A.C from lung mass showed cytological features comprising of few atypical plump, hyperchromatic spindle cells. Conclusion: Haemangiopericytoma of tibia and lung is very rare but is a serious problem even in younger ages. Early diagnosis, regular follow up and proper management may significantly improve the outcome. [ABSTRACT FROM AUTHOR]

Cyclic loading on granular packings and amorphous media exhibits a transition from reversible elastic behavior to irreversible plasticity. The present study compares the irreversibility transition and microscopic details of colloidal polycrystals under oscillatory tensile-compressive and shear strain. Under both modes, the systems exhibit a reversible to irreversible transition. However, the strain amplitude at which the transition is observed is larger in the shear strain than in the tensile-compressive mode. The threshold strain amplitude is confirmed by analyzing the dynamical properties, such as mobility and atomic strain (von Mises shear strain and the volumetric strain). The structural changes are quantified using a hexatic order parameter. Under both modes of deformation, dislocations and grain boundaries in polycrystals disappear, and monocrystals are formed. We also recognize the dislocation motion through grains. The key difference is that strain accumulates diagonally in oscillatory tensile-compressive deformation, whereas in shear deformation, strain accumulation is along the x or y axis.

Background and Objectives: Oral lesions are among the earliest and most important indicators of infection with human immunodeficiency virus (HIV). The presence of oral lesions has a significant impact on the physical and mental health of the PLHIV. Hence, a novel attempt is made to assess the prevalence of various types of oral lesions among the adult people living with human immunodeficiency virus (PLHIV) undergoing antiretroviral therapy., Methodology: In this facility-based cross-sectional study, a total of 239 out of 300 eligible PLHIV were assessed between September and October 2018. All consecutive eligible patients encountered during the data collection period were included. Oral examination was carried out using disposable mouth mirrors, sterile piece of cotton, and bright illuminated torch., Results: The prevalence of oral mucosal abnormalities was found to be 25% (95% confidence interval: 20.03-30.97). The most prevalent oral lesions were acute necrotizing ulcerative gingivitis, acute necrotizing ulcerative periodontitis, and candidiasis. CD4 count <200 cells/mm 3 , current tobacco use, and alcohol usage were significantly associated with the prevalence of oral lesions., Conclusion and Recommendations: The study revealed that one-fourth of the study participants had oral lesions. Strategies for early detection and prompt treatment of oral lesions need to be planned and incorporated in the program to reduce the morbidity due to oral lesions., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Indian Journal of Community Medicine.)

Context: Nationwide lock down imposed due to Covid 19 might bring about various social problems, constraints in availing essential services, difficulty in taking care of morbid elderly persons and inaccessibility to health care which can lead to stress., Aims: To identify social problems among adult Indian residents during lockdown period, to assess perceived stress among them and to identify the factors associated with it., Settings and Design: The study was conducted through the online platform using a google form among adult residents of India. Perceived stress was assessed by Perceived Stress Scale 10., Statistical Analysis Used: Data were analysed using SPSS version 16.0., using chi square, Odd's Ratio and binary logistic regression., Results: One fourth of the respondents faced economic problem, 11.7% of them had experienced some sort of violence and worsening of familial relationship. The problems encountered in seeking care were chi square test due to non availability of transportation facilities and health services. Overall 80.78% of the respondents were observed to have moderate and high levels of perceived stress. Multivariate analysis revealed single marital status, owing a debt and experiencing violence had 1.62, 1.8 and 9 times higher odds of having moderate to high perceived stress. Violence was identified as its chief correlate., Conclusions: The present study found negative economic and social consequences on the Indian population and also posed an enormous psychological stress due to sudden lock down in pandemic situation., Competing Interests: There are no conflicts of interest., (Copyright: © 2021 Journal of Family Medicine and Primary Care.)

Complex fluids made of liquid crystals (LCs) and small molecules, surfactants, nanoparticles or 1D/2D nanomaterials show novel and interesting features, making them suitable materials for various applications starting from optoelectronics to biosensing. While these additives (impurities) introduce new features in the complex fluids, they may also alter the phase transition behaviour of LCs depending on the physiochemical properties of the added impurity. This article reports on the phase transition of 4-cyano-4'-alkylbiphenyl (nCB) LCs in the presence of an associative impurity, i.e., water and a non-associative impurity, i.e., hexane employing computational methods and experiments. In particular, all-atom (AA) simulations and coarse-grained (CG) models were designed for two complex systems, i.e., 6CB + water and 6CB + hexane and corresponding spectrophotometry experiments were performed using a homologous LC, i.e., 5CB. Results from the simulations and experiments elucidate that the phase transition of LCs depends on the mixing/demixing phenomenon of the impurity in the LC. While associative liquids like water which do not mix with LCs do not influence the nematic-to-isotropic phase transition of LCs, hexane, being a non-associative liquid, mixes well with LCs and induces a sharp impurity-induced nematic-to-isotropic phase transition. Upon application of both AA and CG simulations, we could reach the conclusion that the mixing/demixing phenomenon in an LC + impurity system influences the entropy of the system and hence the observed phase transitions are entropy-driven.

Background: In medical education, the learning-teaching method is an active process in which both students and teachers have to work mutually to enlighten the knowledge. Currently, in India, there is an increase in the enrollment of students in medical fields and thus medical educators face the challenge of teaching larger classes in a short period. Furthermore, it is observed that there is a lack of consensus about the best teaching and learning methods for medical students. This study aims to assess the preference of teaching methods and identify the reason for absenteeism among medical undergraduate students in a tertiary care teaching hospital., Materials and Methods: A cross-sectional study was conducted among 246 medical undergraduate students in a tertiary care teaching hospital from August 2019 to October 2019. A pretested, validated self-administered questionnaire was used to assess the preference of teaching methods. The data were analyzed using SPSS-IBM software 23., Results: The majority of the students belonged to 20-21 years of age group. Most of the students preferred practical demonstration (81.3%) as the preferred method of teaching and computer with a liquid crystal display projector as ideal media for teaching (63.8%). Boring/monotonous teaching class was found (73.5%) to be an important cause for absenteeism among medical undergraduate students., Conclusion: The results indicate that the medical student's preference is changing from passive learning to active learning. We conclude by linking these emerging perceptions with suggestions to help drive excellence in medical education., Competing Interests: There are no conflicts of interest., (Copyright: © 2020 Journal of Education and Health Promotion.)

DNA-mediated multivalent interactions between colloidal particles have been extensively applied for their ability to program bulk phase behaviour and dynamic processes. Exploiting the competition between different types of DNA-DNA bonds, here we experimentally demonstrate the selective triggering of colloidal self-assembly in the presence of a functionalised surface, which induces changes in particle-particle interactions. Besides its relevance to the manufacturing of layered materials with controlled thickness, the intrinsic signal-amplification features of the proposed interaction scheme make it valuable for biosensing applications.

One of the challenges of self-assembling finite-sized colloidal aggregates with a sought morphology is the necessity of precisely sorting the position of the colloids at the microscopic scale to avoid the formation of off-target structures. Microfluidic platforms address this problem by loading into single droplets the exact amount of colloids entering the targeted aggregate. Using theory and simulations, in this paper, we validate a more versatile design allowing us to fabricate different types of finite-sized aggregates, including colloidal molecules or core-shell clusters, starting from finite density suspensions of isotropic colloids in bulk. In our model, interactions between particles are mediated by DNA linkers with mobile tethering points, as found in experiments using DNA oligomers tagged with hydrophobic complexes immersed into supported bilayers. By fine-tuning the strength and number of the different types of linkers, we prove the possibility of controlling the morphology of the aggregates, in particular, the valency of the molecules and the size of the core-shell clusters. In general, our design shows how multivalent interactions can lead to microphase separation under equilibrium conditions.

Much work has studied effective interactions between micron-sized particles carrying linkers forming reversible, interparticle linkages. These studies allowed understanding the equilibrium properties of colloids interacting through ligand-receptor interactions. Nevertheless, understanding the kinetics of multivalent interactions remains an open problem. Here, we study how molecular details of the linkers, such as the reaction rates at which interparticle linkages form or break, affect the relative dynamics of pairs of cross-linked colloids. Using a simulation method tracking single binding and unbinding events between complementary linkers, we rationalize recent experiments and prove that particles' interfaces can move across each other while being cross-linked. We clarify how, starting from diffusing colloids, the dynamics become arrested when increasing the number of interparticle linkages or decreasing the reaction rates. Before getting arrested, particles diffuse through rolling motion. The ability to detect rolling motion will be useful to shed new light on host-pathogen interactions.

Polyelectrolyte multilayers (PEM) obtained by layer-by-layer assembly can be doped with ionic liquid (IL) via the swelling of the films with IL solutions. In order to examine the mechanical properties of IL-containing PEM, we implement a Kelvin-Voigt model to obtain thickness, viscosity and elastic modulus from the frequency and dissipation shifts determined by a dissipative quartz crystal microbalance (QCM-D). We analyze the changes in the modeled thickness and viscoelasticity of PEI(PSS/PADMAC) 4 PSS and PEI(PSS/PAH) 4 PSS multilayers upon swelling by increasing the concentration of either 1-Ethyl-3-methylimidazolium chloride or 1-Hexyl-3-methylimidazolium chloride, which are water soluble ILs. The results show that the thickness of the multilayers changes monotonically up to a certain IL concentration, whereas the viscosity and elasticity change in a non-monotonic fashion with an increasing IL concentration. The changes in the modeled parameters can be divided into three concentration regimes of IL, a behavior specific to ILs (organic salts), which does not occur with swelling by simple inorganic salts such as NaCl. The existence of the regimes is attributed to a competition of the hydrophobic interactions of large hydrophobic ions, which enhance the layer stability at a low salt content, with the electrostatic screening, which dominates at a higher salt content and causes a film softening.

Functionalizing colloids with reactive DNA linkers is a versatile way of programming self-assembly. DNA selectivity provides direct control over colloid-colloid interactions allowing the engineering of structures such as complex crystals or gels. However, the self-assembly of localized and finite structures remains an open problem with many potential applications. In this work, we present a system in which functionalized surfaces initiate a cascade reaction between linkers leading to the self-assembly of crystals with a controllable number of layers. Specifically, we consider colloidal particles functionalized by two families of complementary DNA linkers with mobile anchoring points, as found in experiments using emulsions or lipid bilayers. In bulk, intra-particle linkages formed by pairs of complementary linkers prevent the formation of inter-particle bridges and therefore colloid-colloid aggregation. However, colloids interact strongly with the surface given that the latter can destabilize intra-particle linkages. When in direct contact with the surface, colloids are activated, meaning that they feature more unpaired DNA linkers ready to react. Activated colloids can then capture and activate other colloids from the bulk through the formation of inter-particle linkages. Using simulations and theory, validated by existing experiments, we clarify the thermodynamics of the activation and binding process and explain how particle-particle interactions, within the adsorbed phase, weaken as a function of the distance from the surface. The latter observation underlies the possibility of self-assembling finite aggregates with controllable thickness and flat solid-gas interfaces. Our design suggests a new avenue to fabricate heterogeneous and finite structures.

Multivalent adhesive interactions mediated by a large number of ligands and receptors underpin many biological processes, including cell adhesion and the uptake of particles, viruses, parasites, and nanomedical vectors. In materials science, multivalent interactions between colloidal particles have enabled unprecedented control over the phase behavior of self-assembled materials. Theoretical and experimental studies have pinpointed the relationship between equilibrium states and microscopic system parameters such as the ligand-receptor binding strength and their density. In regimes of strong interactions, however, kinetic factors are expected to slow down equilibration and lead to the emergence of long-lived out-of-equilibrium states that may significantly influence the outcome of self-assembly experiments and the adhesion of particles to biological membranes. Here we experimentally investigate the kinetics of adhesion of nanoparticles to biomimetic lipid membranes. Multivalent interactions are reproduced by strongly interacting DNA constructs, playing the role of both ligands and receptors. The rate of nanoparticle adhesion is investigated as a function of the surface density of membrane-anchored receptors and the bulk concentration of nanoparticles and is observed to decrease substantially in regimes where the number of available receptors is limited compared to the overall number of ligands. We attribute such peculiar behavior to the rapid sequestration of available receptors after initial nanoparticle adsorption. The experimental trends and the proposed interpretation are supported by numerical simulations.

Liquid crystals have emerged as potential candidates for next-generation lubricants due to their tendency to exhibit long-range ordering. Here, we construct a full atomistic model of 4-cyano-4-hexylbiphenyl (6CB) nematic liquid crystal lubricants mixed with hexane and confined by mica surfaces. We explore the effect of the surface structure of mica, as well as lubricant composition and thickness, on the nanoscale friction in the system. Our results demonstrate the key role of the structure of the mica surfaces, specifically the positions of potassium (K+) ions, in determining the nature of sliding friction with monolayer lubricants, including the presence or absence of stick-slip dynamics. With the commensurate setup of confining surfaces, when the grooves created between the periodic K+ ions are parallel to the sliding direction we observe a lower friction force as compared to the perpendicular situation. Random positions of ions exhibit even smaller friction forces with respect to the previous two cases. For thicker lubrication layers the surface structure becomes less important and we observe a good agreement with the experimental data on bulk viscosity of 6CB and the additive hexane. In case of thicker lubrication layers, friction may still be controlled by tuning the relative concentrations of 6CB and hexane in the mixture.

Cyclically loaded disordered particle systems, such as granular packings and amorphous media, display a non-equilibrium phase transition towards irreversibility. Here, we investigate numerically the cyclic deformation of a colloidal polycrystal with impurities and reveal a transition to irreversible behavior driven by the displacement of dislocations. At the phase transition we observe enhanced particle diffusion, system size effects and broadly distributed strain bursts. In addition to provide an analogy between the deformation of amorphous and polycrystalline materials, our results allow to reinterpret Zener pinning of grain boundaries as a way to prevent the onset of irreversible crystal ordering.

We describe experiments and computer simulations of molecular deposition on a substrate in which the molecules (substituted adenine derivatives) self-assemble into ordered structures. The resulting structures depend strongly on the deposition rate (flux). In particular, there are two competing surface morphologies (α and β), which differ by their topology (interdigitated vs lamellar structure). Experimentally, the α phase dominates at both low and high flux, with the β phase being most important in the intermediate regime. A similar nonmonotonic behavior is observed on varying the substrate temperature. To understand these effects from a theoretical perspective, a lattice model is devised which reproduces qualitatively the topological features of both phases. Via extensive Monte Carlo studies we can, on the one hand, reproduce the experimental results and, on the other hand, obtain a microscopic understanding of the mechanisms behind this anomalous behavior. The results are discussed in terms of an interplay between kinetic trapping and temporal exploration of configuration space.

Application of intramolecular 1,3-dipolar nitrone cycloaddition reaction on carbohydrate-derived precursors containing an olefin functionality at C-1 or C-3 or C-5 and a nitrone moiety at C-2 or C-3 as appropriate has resulted in the formation of structurally new cycloaddition products containing furanose-fused oxepane, thiepane, azepane, cyclopentane, cycloheptane, tetrahydrofuran, and pyranose-fused tetrahydrofuran rings. The structure and stereochemistry of these products have been characterized by spectral as well as single-crystal X-ray analyses. Two of the compounds have been transformed to the bicyclic nucleoside derivatives applying Vorbrüggen reaction conditions.

Large-area self-assembled structures of a nucleobase adenine derivative were successfully realized through vacuum deposition. STM images reveal two types of structures, which could be regulated by substrate temperature and the evaporation rate, indicating the relevance of kinetic effects. The results are supported by computer simulations.

The self-organization of lipophilic chain molecules on surfaces in vacuum deposition experiments has been recently studied by Monte Carlo simulations of a coarse grained microscopic model system. Surprisingly, the final potential energy depends in a non-monotonous way on the chosen flux and the surface temperature. Here we introduce a schematic model which contains the relevant physical ingredients of the microscopic model and which elucidates the origin of this anomalous non-equilibrium effect. Intra-cluster effects, reflecting the chain arrangement within one cluster, and inter-cluster effects, based on the distribution of chains among the different formed clusters, are taken into account. This schematic model is solved numerically as well as via analytical means. From the analytical solutions, it is possible to understand quantitatively for which interaction parameters the observed anomalies can indeed be observed. The generality of the observed phenomena is stressed. It is related to the concept of kinetic trapping, which often occurs during self-assembly.

Model chains are studied via Monte Carlo simulations which are deposited with a fixed flux on a substrate. They may represent, e.g., stiff lipophilic chains with an head group and tail groups mimicking the alkyl chain. After some subsequent fixed simulation time we determine the final energy as a function of flux and temperature. Surprisingly, in some range of temperature and flux the final energy increases with decreasing flux. The physical origin of this counterintuitive observation is elucidated. In contrast, when performing equivalent cooling experiments no such anomaly is observed. Furthermore, it is elaborated whether flux experiments give rise to configurations with lower energies as compared to cooling experiments. These results are related to recent experiments by the Ediger group where very stable configurations of glass-forming systems have been generated via flux experiments.

A bifid sternum is a rare congenital anomaly generally diagnosed as asymptomatic at birth. It is sometimes associated with other congenital anomalies. The sternal defects are best corrected surgically during the neonatal period within the first month of life. Sometimes the defect may be diagnosed only in adult life. We here report a case of bifid sternum which was diagnosed incidentally in a 23-year-old male.

A 22 years old female presented with fever, respiratory distress and a rapidly enlarging, soft left postauricular lump for last two months. She was found anaemic, had a right supraclavicular, non-tender lymph node of about 2.5 cm diameter and mild hepatosplenomegaly. She had a positive Mantoux test, and normal chest x-ray. Ultrasonography of abdomen showed multiple pre-and para-aortic enlarged lymph nodes. Mild pericardial effusion was detected on echocardiography. Fine needle aspiration cytology from the right supraclavicular lymph node showed epithelioid cell granuloma. Excision and biopsy of the dermoid were carried out. The content was pus, which was smear-negative but culture-positive for acid-fast bacilli. The patient responded to antituberculous chemotherapy satisfactorily.

The pH titration of nine amino acids (glycine, proline, valine, serine, glutamine, tryptophan, arginine, histidine and aspartic acid) in presence of urea in the concentration range 1-8 mole dm-3 has been performed. The results support suppression of the first dissociation constant (K1) of the amino acids and acceptance of H+ ions by the amide forming uronium ion (UH+). The second dissociation constant (K2) of the amino acids is affected relatively weakly by urea. Quantitative evaluation of different species existing in solution and the degree of dissociation of the acids as well as the degree of binding of H+ ion to the amide have been made. It has been found that the polarity of the aqueous-urea medium does not straight forwardly correlate with the altered pK1 of the amino acids. Urea can also affect the pH-titration behaviour of gelatin with an increase of the intrinsic pK of the acidic groups of the protein by 0.45 unit.